Yes, the shipyard period will include cabin updates where they will replace worn items and do other enhancements. I believe some new cabins will be installed too, which will take away a couple of mostly underused public areas on decks 7 and 8.

Also note that cabin numbering will change on those two decks. Recently some people with cruises booked on Rhapsody Of The Seas got hosed since they booked prior to the upgrades, and after the upgrades the cabins they had (aft corner balconies which are highly desirable) were now reassigned by the new cabin numbers to become standard issue side balconies. By the time the passengers realized it, other people had booked the newly renumbered cabins on the aft corners and got the prime locations. RCI did the people who booked earlier wrong.